Since I primarily hunt in places that tend to be cold and wet, I'd say warm, dry clothes and boots. Or perhaps more accurately, my ability to afford such things was the critical development?
Never owned a good pair of water proof insulated huntng boots until into my 30s. Or any good rain gear until later than that.
Not much call for electronics where and how I hunt most of the time, although I've had a compact 800 yard laser range finder for years.
Acquired topo maps for the areas I generally hunt deer in, many years ago.
